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LAPACK version 3.0
ztrtrs(3)

PURPOSE
  ZTRTRS - solve a triangular system of the form  A * X = B, A**T * X = B, or
  A**H * X = B,

SYNTAX
  SUBROUTINE ZTRTRS( UPLO, TRANS, DIAG, N, NRHS, A, LDA, B, LDB, INFO )

      CHARACTER	     DIAG, TRANS, UPLO

      INTEGER	     INFO, LDA, LDB, N, NRHS

      COMPLEX*16     A( LDA, * ), B( LDB, * )

DESCRIPTION
  ZTRTRS solves a triangular system of the form A * X = B, A**T * X = B, or
  A**H * X = B, where A is a triangular matrix of order N, and B is an N-by-
  NRHS matrix.	A check is made to verify that A is nonsingular.

ARGUMENTS
  UPLO	  (input) CHARACTER*1
	  = 'U':  A is upper triangular;
	  = 'L':  A is lower triangular.

  TRANS	  (input) CHARACTER*1
	  Specifies the form of the system of equations:
	  = 'N':  A * X = B	(No transpose)
	  = 'T':  A**T * X = B	(Transpose)
	  = 'C':  A**H * X = B	(Conjugate transpose)

  DIAG	  (input) CHARACTER*1
	  = 'N':  A is non-unit triangular;
	  = 'U':  A is unit triangular.

  N	  (input) INTEGER
	  The order of the matrix A.  N >= 0.

  NRHS	  (input) INTEGER
	  The number of right hand sides, i.e., the number of columns of the
	  matrix B.  NRHS >= 0.

  A	  (input) COMPLEX*16 array, dimension (LDA,N)
	  The triangular matrix A.  If UPLO = 'U', the leading N-by-N upper
	  triangular part of the array A contains the upper triangular
	  matrix, and the strictly lower triangular part of A is not
	  referenced.  If UPLO = 'L', the leading N-by-N lower triangular
	  part of the array A contains the lower triangular matrix, and the
	  strictly upper triangular part of A is not referenced.  If DIAG =
	  'U', the diagonal elements of A are also not referenced and are
	  assumed to be 1.

  LDA	  (input) INTEGER
	  The leading dimension of the array A.	 LDA >= max(1,N).

  B	  (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
	  On entry, the right hand side matrix B.  On exit, if INFO = 0, the
	  solution matrix X.

  LDB	  (input) INTEGER
	  The leading dimension of the array B.	 LDB >= max(1,N).

  INFO	  (output) INTEGER
	  = 0:	successful exit
	  < 0: if INFO = -i, the i-th argument had an illegal value
	  > 0: if INFO = i, the i-th diagonal element of A is zero,
	  indicating that the matrix is singular and the solutions X have not
	  been computed.